As a first prior art for grasping a connection situation of a terminal with an AP, there exists the function installed into an AP management tool attached to an AP product (For example, non-patent document 1). The above prior art provides the function that each AP collects information associated with the connection situation of the terminal, and supplies to the monitor apparatus connection information of the terminal in a unique format, which is text-displayed in a table format on a screen of the monitor apparatus (for example, a PC having a Web browser installed). The so-called uniquely format includes, for example, information uniquely specified by a vendor as MIB information (Management Information Base) of an SNMP (Simple Network Management Protocol), information uniquely specified by a vendor that is included in a HTTP (Hyper Text Transfer Protocol), a uniquely specified protocol, or the like. These formats, which are disclosed in some cases, are used only for its vendor's appliances.
As a second prior art, the technology that the monitor apparatus receives a broadcast packet of a wireless LAN, transmits a dummy packet to a transmission-source address of the same packet, and confirms its reply, thereby allowing a terminal-connection relation to be collected and to be displayed has been proposed (for example, patent document 1). In this technology, the apparatus for monitoring a connection relation is installed network by network.    Non-patent document 1: Cisco Systems Lnc., Association Table described in an Internet<http://www2.hipri.com/cisco_pdf/pdfsearch/displayPDF/OL—06 57—08/0657—08.PDF9-2>    Patent document 1: JP-P1995-297852A